Process of treating methane gas



G. OLIVIER PROCESS OF TREATING METHANE GAS July 17, 1928.

Filed June 3, 1926 in ven tor Georyes Olivier Affornc Patented Jul 17, 192a UNITED STATES I r 1,677,363 PATENT orFlcE.

GEORGES OLIVIER, OF ASNIERES, FRANCE, ASSIGNOR TO SOCIETE ANONYME LE PETROLE SYNTHETIQUE, OF AS NIERES, FRANCE.

Application filed June 3, 1928, Serial No.

The object of the present invention is to provide a process for continuously converting methane gas into hydrocarbons of higher carbon content, chiefly ethylenic hydrocar- 6 bons, with the liberation of active hydrogen.

It has been known for a long time that methane (CH,) passed throu h a orcelain tube at moderately red heat. glves rise to the formation of ethylene (QH and its more 10 condensed homologues such as propylene. The products of the reaction are then found to contain 'a small amount of acetylene (C,H and even of ethane These reactions are limited by the possi-' 1 bility of reverse reactions corresponding to a state of equilibrium according to experimental conditions such as the gas velocity, pressures, temperatures etc. Furthermore it was not heretofore found possible toprevent the formation of napbthalen'e and other pyrogenated hydrocarbons capable of clogging the apparatus.

The present invention 'is based on a thorough study of the influences on the reactions of the time, velocity, temperature and pressure factors, which made it possible to ascertain the conditions of equilibrium and led to -a process avoiding the above inconveniences and adapted to give well defined results.

This process is characterized by the simultaneous fulfilment of three essential conditions viz, the gradual and uniform heating of athin layer or stream'of methane, the

continuous suction of the gases produced and the sudden and complete cooling of these gases down to atmospheric temperature. I am thus enabled to obtain a continuous conversion of the methane gas into 40 ethylenic hydrocarbons and other gaseous hydrocarbons of higher carbon content, with a maximum output of well defined products adapted for subsequent industrial use and with liberation of active hydrogen, while the'p'roduction of naphthalene and other pyrogenated hydrocarbons is avoided.

Concernin the industrial use of the products obtaine I mav mention the synthetic production of alcohol from ethylene and that of liquid hydrocarbons analogous to petroleum oils.

In practice the process according to this invention is carried out by passing the methane gas in a very thin stream, prefernas sa, and in France February a, 1926.

ably of annular cross-section and havin a. thickness which may be as little. as 1 millimeter, between two refractory walls suitably heated so as gradually to bring the methane to a temperature which may reach 950 C. I am thus enabled to avo d temperature and velocity variations within the gas to be treated and the obnoxious reactions resulting therefrom, which could not be avoided in an ordinary porcelain tube;

On the other hand I maintain within the system a vacuum of about 20 centimeters of mercury in order to provide for the desired continuous suction of the gaseous products. I thus exclude the possibility of reverse reactions which would be promoted by a rise in the pressure.

F inallythe sudden cooling of the gases produced efliciently checks any subsequent reaction.

\Vith pure methane I thus obtain in a practical manner its nearly complete conversion intoethylenic hydrocarbons C..H. in preponderant pro ortion, with liberation of active hydrogen, t e rest of the mixture consisting chiefly of saturated hydrocarbons C H, The activit of the hydrogen set free results, as is well known, from its libs eration at a high temperature followed by sudden cooling.

\Vith a natural gas such as the/gas o Vaux (Ain) containin about 80% .of CH. 6% of H 25% of C 2,(i% of C H,, etc., it is possible continuously to convert in.a single operation about 80% of the GIL into t tlglene, 0 H and ethylenic hydrocarbons The accompanying drawing illustrates diagrammatically by way of example, an apparatus suitable for carrying out the process according to this invention.

The a paratus shown comprises a suitable num er of refractory tubes 1 connected in series by means of pipes 4. Each tube l is mounted within a metal tube 10 and con-. tains a refractory cylindrical core 2 centered so as to form with the inner wall of tube 1 an annular space of a uniform thickness of a couple of millimeters.

The tubes 10 are fitted in a as-tight manner in chambers 3, 3", 3 w ich are, connected onone side with a chamber 3 heated by a furnace, burners or otherwise, and on the other with a chamber 3 leading to the I so roducts of combustion circuchimney, the

irection ofthe slngle headed lating m the arrows,

The gas to be treated flows through the pipes 4 and the tubes-1 in the direction of the double-headed arrows, and passes from the annular space in each tube 1 to the next pipe 4 through perforations 5 provided under the cylindrical core 2. This gas is gradually heated in the chambers 3, 3",

reaches its highest temperature in chamber 3 and "as it issues therefrom it is suddenly cooled by passing through a water cooler (i whence it is sucked, through a pipe 7, by a pump 8 which maintains the required degree of vacuum within the tubular system and compresses the gasto a pressure'-suit-- able for storing or for subsequent treatment. It will be understood that other apparatus maybe devised in order to' realize the three conditions the-fulfilment of which is the characteristic feature of the present inven- .tion.-

IcIairn:

1. A process of converting methane gas into hydrocarbons of higher carbon content, consistin" stream of metliane to a temperature not excecding 950 C. which will form ethylene and ethylenie compounds, subjecting the products formedt-o a vacuum, and suddenly. and completely cooling said products down to atmospheric temperature. a.

2. A )r'ocess .ofi'converting methane gas into by rocarbons of highercarboxrcmitcnt, consistingin gradually heating 'athin stream of methane to atemperatm'enot excecdiug 950 :C. at which ethylene and ethylcuic com pounds are formed; sul'ijccting :the products formed to avacuum,and-suddenly and cdhu'wletcly cooling said products-down to atmospheric temperature immediately a l't-cr .tho, 'l lighest temperature has been reaclwd. Y

3. A process of treating methane gas consisting m gradually heating a? thi'n stream end thereof to the other, thereby heating said in gradually heating a thin.

of methane to a temperature not exceeding 950 C. which will form ethylene and ethylcnic hydrocarbons, suddenly cooling said hydrocarbons down to atmos hcric temperature and subjecting said by rocarbons to a vacuum from the time they are formed until after they are completely cooled. v

4. A process of convertingmethane gas into hydrocarbons of higher carbon content, consisting in continuously passing a stream of methane through a narrow passage, heating the walls of seal-passage to tempel'ul-lu'os gradually increasing from one denly cooling the products coming out of. the hottest zone and maintaining said vacuum until said products ln1,\l"e:-- been cornpletely cooled dowxr to-"atlnosfilieiie temperature. I .6. A- proccss iofi c mvert ing methan eFgass, into hydrocarbons of higher-carbon consisting in continuously passing of methane between walls space one to three millimeters, gr'gi c said stream to a-temperature}iiotf-exceedilu 950 (k that will; form etllyleuel' and ethyl; enic compounds subjecting F the -p'roducts 5 formed toa vacuum, and suddenly and-coins",

eEoReEsomlyIER;

pletely coolingthe products ito atmospheric 00' temperature. 

